• Membrane Journal
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• v.24 no.6
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• pp.453-462
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• 2014

Thin film composite (TFC) polyamide (PA) membranes were prepared on polyester (PET) nonwoven reinforced polysulfone supports for forward osmosis (FO) processes. PSF (polysulfone) supports were prepared via the phase inversion process from PSF casting solutions in dimethyl formamide (DMF) solvents (19 wt%) by using a PET nonwoven (thickness of $100{\mu}m$) as a mechanical reinforcing material for reverse osmosis (RO) membrane. The PSF support from 19 wt% of DMF/PSF casting solution showed sponge-like morphology and asymmetric internal structure. To reduce the internal concentration polarization in FO operation, thin ($20{\mu}m$ of thickness) nonwoven-supported PSF supports were prepared by using PSF/DMF casting solution (9~19 wt%). A desirable support structure with a highly porous sponge-like morphology were achieved from the thin nonwoven-supported PSF layer prepared with 9~12 wt% casting solution. A crosslinked aromatic polyamide layer was fabricated on top of each support to form a TFC PA membrane. The tested sample from 12 wt% of DMF/PSF casting solution presented outstanding FO performance, almost 5.5 times higher water flux (24.3 LMH) with low reverse salt flux (RDF, 1.5 GMH) compared to a thick nonwoven rainforced membrane (4.5 LMH of flux and 3.47 GMH of RSF). By reducing the thickness of the nonwoven and optimizing PSF concentration of casting solution, the morphology of the prepared membranes were changed from a dense structure to a porous sponge structure in the boundary area between nonwoven and PET support layer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.117-122
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• 2016

In this paper, we propose 24-GHz CMOS radio frequency (RF) power amplifier for short-range automotive collision avoidance radars. This circuit contains common source stage with inter-stages conjugate matching circuit as a class-A mode amplifier. The proposed circuit is designed using TSMC $0.13-{\mu}m$ mixed signal/RF CMOS process ($f_T/f_{MAX}=120/140GHz$). It operates at the supply voltage of 2V, and it is designed to have high power gain, low insertion loss and low noise figure in the low supply voltage. To reduce total chip area, the circuit used transmission lines instead of the bulky real inductor. The designed CMOS power amplifier showed the smallest chip size of $0.1mm^2$, the lowest power consumption of 40mW, the highest power gain of 26.5dB, the highest saturated output power of 19.2dBm and the highest maximum power-added efficiency of 17.2% as compared to recently reported results.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.19-24
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• 2013

This study is to promote domestic environmentally appropriately conditions for the range 60~70 m, the development of the small and medium-sized sprayer ability measurement that can be used as a general-purpose paddy fields, orchards, and not consolidated areas. The sprayer designed and manufactured that can spraying effectively distance to within 60~70 m. Distribution of sprayed pesticides were obtained and analyzed by measuring the weight. Performance analysed using the buckets were placed horizontally 12.5 m, 70 m vertical intervals by $5m{\times}2.5m$, so total 68 buckets were placed. Total amounts of sprayed quantity was $2,000{\ell}$ and maximum spray distance was about 70 m. Reasonably sprayed region was 5 m~10 m vertically symmetrical. Showed a lot of spraying water in 5 m~40 m distance, and in 45~60 m tended to spraying water decreased slightly. Maximum spraying distance was 70 m.

• Publications of The Korean Astronomical Society
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• v.24 no.1
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• pp.19-34
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• 2009

From the short-period variability survey (SPVS) in Bohyunsan Optical Astronomy Observatory, I obtained time-series BV CCD images in the region of the young open cluster M29 (NGC 6913) for 15 nights from May 30, 2008 to September 17, 2009. I observed 48 variable stars including 45 new ones. They consisted of 5 $\delta$ Scuti, a Cepheid, 16 eclipsing binaries and 24 semi-long periodic and/or slow irregular type variable stars including $\beta$ Cephei and LPB type stars. For the rest two ones, the type of variability was not defined. I also checked the variability of the 26 known variable stars listed in the GCVS. Only three ones among 26 known variable stars confirmed variability.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.502-506
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• 2011

Most countries have the legislation and regulation for POPs control in food. In here, we studied the quantitative analysis of 24 organochlorine POPs (${\alpha}$-HCH 1, ${\beta}$-HCH 2, ${\gamma}$-HCH 3, ${\delta}$-HCH 4, trans-chlrodane 5, 2,4'-DDE 6, ${\alpha}$-endosulfan 7, cis-chlordane 8, 2,4'-DDD 9, endrin 10, ${\beta}$-endosulfan 11, 2,4'-DDT 12, endosulfan sulfate 13, HCB 14, aldrin 15, trans-nonachlor 16, 4,4'-DDE 17, dieldrin 18, 4,4'-DDD 19, cis-nonachlor 20, 4,4'-DDT 21, heptachlor 22, heptachlor epoxide 23 and mirex 24) with GC-ECD. The retention time of analytes were ranged between 19.18 min and 34.69 min, and their peak intervals were over 0.05 min at least. LOQs were ranged 0.003 ~ 0.033 ng/g, and their recovery rates were showed 60.9 ~ 120.8% on the 0.1 ng/g concentration of 24 organochlorine POPs. All tested 30 sundried salts were collected on Korean retailed market, and any analyte was not found in all the samples on LOQ levels.

• Journal of Applied Biological Chemistry
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• v.49 no.1
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• pp.24-27
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• 2006

Four ursane-type triterpenoids, 2${\alpha}$,3${\alpha}$,19${\alpha}$-trihydroxy-24-norurs-4(23),12-dien-28-oic acid (1), 4(R),23-epoxy-2${\alpha}$,3${\alpha}$,19${\alpha}$-trihydroxy-24-norurs-12-en-28-oic acid (2), myrianthic acid (3), and tormentic acid (4), and a phenolic compound, ethyl gallate (5), from an EtOAc-soluble extract of the stems of Rumex japonicus, were subjected to in vitro bioassays to evaluate advanced glycation end products (AGEs) and rat lens aldose reductase (RLAR) inhibitory activity. Compounds 1 and 5 exhibited a significant inhibitory activity on AGEs formation with $IC_{50}$ value of 87 ${\mu}M$ and on RLAR with $IC_{50}$ value of 14.3 ${\mu}M$, respectively. Ethyl gallate (5) was isolated for the first time from this plant.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.3 no.1
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• pp.13-21
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• 1989

A clinico-statistical analysis was performed on 1373 cases who complained of hoarseness at the Dept. of Otolaryngology of Ewha Womans University hopital during the past 10 years from fan 1975 to Dec 1984 and the following results were obtained. 1) Among total of 44,912 who visited the Dept. of Otolaryngology. the patients with hoarseness were 1373 cases(3.1%). 2) Among total of 1373 cases, male were 586 and female were 787, the ratio being 1:1.3. 3) The underlying diseases causing hoarseness in order of frequency were acute laryngitis 374 cases(27.2%), chronic laryngitis 325 cases(23.7%), vocal nodule 248 cases(18.1%), vocal polyp 130 cases(9.5%), vocal cord paralysis 101 cases(7.4%), laryngeal cancer 24 cases(1.7%). 4) The highest incidence of age causing hoarseness in order of frequency were 3rd decade 368 cases(26.8%) 2nd decade 312 cases(22.7%) 4th decade 297 cases(21.6%), 5) The highest incidence of age for underlying diseases in order of frequency were as that follows: acute laryngitis in 2nd decade 114 cases(30.5%), chronic laryngitis in 3rd decade 92 cases(28.3%), vocal nodule in 3rd decade 81 cases(32.7%), vocal polyp in 4th decade 38 cases(29.2%), vocal cord paralysis in 5th decade 19 cases(18.8%), laryngeal cancer in 5th decade 13 cases(54.2%). 6) Number of the patients who came the hospital within 10 days after the onset of hoarseness were 272 cases(19.8%), 15 cases(1.1%) had medical attention for first time 10 years after hoarseness. 7) The highest incidence of the duration from the onset to consultation for the underlying diseases were as that follows: acute larynsitis within 10 days 205 cases(54.8%), chronic laryngitis 3M-6M 76 cases(23.4%), vocal nodule 3M-6M 55 cases(22.2%) vocal polyp 6M-lYr 32 cases(24.6%), vocal cord paralysis 3M-6M 20 cases(19.8%)

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7195-7200
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• 2014

Background: The aim of this study was to evaluate how CYP2C19 affects icotinib and metabolite' exposure, and to determine whether the exposure and EGFR genotype influences survival time, tumor metastasis and adverse drug reactions. Materials and Methods: 274 NSCLC patients who accepted 125mg icotinib/t.i.d. were chosen from a phase III study. Blood samples were obtained in $672^{nd}$ ($4^{th}$ week) and $1,680^{th}$ hours ($10^{th}$ week), and plasma was used to quantify the concentration of icotinib and blood cells were sampled to check the genotypes. Clinical data were also collected at the same time, including EGFR genotypes. Plasma concentrations were assessed by HPLC-MS/MS and genotype by sequencing. All data were analyzed through SPSS 17.0 and SAS 9.2. Results: CYP 2C19 genotypes affected bio-transformation from icotinib to M24 and M26, especially in poor-metabolisers. Higher icotinib concentrations (>1000 ng/mL) not only increased patient PFS and OS but also reduced tumor metastasis. Patients with mutant EGFR experienced a higher median PFS and OS (234 and 627 days), especially those with the 19del genotype demonstrating higher PR ratio. Patients who suffered grade II skin toxicity had a higher icotinib exposure than those with grade I skin toxicity or no adverse effects. Liver toxic reactions might occur in patients with greater M20 and M23 plasma concentrations. Conclusions: CYP2C19 polymorphisms significantly affect icotinib, M24 and M26 exposure. Patients with mutant EGFR genotype and higher icotinib concentration might have increased PFS and OS and lower tumor metastasis. Liver ADR events and serious skin effects might be respectively induced by greater M20, M23 and icotinib concentrations.

• Journal of the Korean Statistical Society
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• v.24 no.1
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• pp.19-29
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• 1995

In this paper, we investigate the asymptotic distributions of maximum queue length for M/G/1 and GI/M/1 systems which are positive recurrent. It is well knwon that for any positive recurrent queueing systems, the distributions of their maxima linearly normalized do not have non-degenerate limits. We show, however, that by concerning an array of queueing processes limiting behaviors of these maximum queue lengths can be established under certain conditions.

• Journal of Environmental Science International
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• v.24 no.10
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• pp.1265-1272
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• 2015

To investigate the thermal environment over the summertime asphalt pavements, an automatic weather observation system was installed at a parking lot paved with asphalt to observe various meteorological parameters and surface temperature from July 1 to September 30, 2014. Since the number of rainy days in summer of 2014 particularly after the mid July is more than that of average data, a ratio of daily peak surface temperature above $45^{\circ}C$ was 28% which was lower than the average. The observational data about hourly average surface temperature and various heat balance factors at days where daily peak surface temperature is above $45^{\circ}C$ are as follows: An hour that had the daily maximum temperature was around 15 pm and the value was $49^{\circ}C$ approximately. Net shortwave radiation was the highest at 12pm as $800W/m^2$ and much radiation of $500W/m^2$ was absorbed at the ground between 11am and 17pm. Sensible heat that was delivered from the ground to the atmosphere was evaluated as $200W/m^2$ between 10am and 19pm. underground transfer heat up to $100W/m^2$ was measured as negative from 19pm to the next day 8am, which indicated the lower atmosphere was heated at night.